苦参碱对金黄色葡萄球菌入侵BMECs的干预作用

Effect of matrine on invasion of bovine mammary epithelial cells by Staphylococcus aureus

【目的】研究苦参碱在金黄色葡萄球菌入侵奶牛乳腺上皮细胞(BMECs)过程中的干预作用及其原因,为苦参碱的临床应用奠定基础。【方法】用CCK-8法检测苦参碱对BMECs增殖的影响,用庆大霉素保护试验检测苦参碱对金黄色葡萄球菌入侵BMECs的影响;并在苦参碱干预金黄色葡萄球菌感染BMECs后,分别采用RT-qPCR检测BMECs中抗菌肽基因的表达,Greiss法检测NO的分泌,Western blot检测NF-κB通路蛋白p65的表达。【结果】25~100μg/mL苦参碱均能促进BMECs的增殖,并能抑制金黄色葡萄球菌入侵BMECs;苦参碱干预能显著下调BMECs中抗菌肽基因TAP和BNBD5 mRNA的表达,抑制NO的分泌和NF-κB的活化,并呈剂量依赖性。【结论】苦参碱通过抑制NF-κB的活化来抑制金黄色葡萄球菌入侵BMECs,并可显著下调金黄色葡萄球菌感染的BMECs中抗菌肽基因的表达。

【Objective】This study investigated the intervention effect and causes of matrine on the invasion process of Staphylococcus aureus to bovine mammary epithelial cells(BMECs)to provide basis for the clinical application of matrine.【Method】Effect of matrine on the proliferation of BMECs was detected by CCK-8 assay.Thereafter,the effect on BMECs invaded by S.aureus was detected by gentamicin protection test.The mRNA expression levels of antimicrobial peptide from S.aureus infected BMECs induced by matrine were determined by RT-qPCR.The NO secretion in BMECs was analyzed by the Greiss method.The effect of matrine on the expression of NF-κB pathway protein p65 was determined by the Western blot.【Result】Matrine can promote the proliferation of BMECs and inhibit the invasion of S.aureus at the concentration of 25-100μg/mL.Matrine can significantly down-regulate the mRNA expression levels of tracheal antimicrobial peptide(TAP)and bovine neutrophil beta-defensin 5(BNBD5)in BMECs infected by S.aureus.Matrine can inhibit the NO production in BMECs infected by S.aureus.Matrine can inhibit the activation of NF-κB in BMECs infected by S.aureus in a dose-dependent manner.【Conclusion】Matrine can suppress the invasion of S.aureus by inhibiting the activation of NF-κB pathway and significantly down-regulate the expression of antibacterial peptide genes in BMECs infected by S.aureus.